Reference is made to U.S. Pat. No. 4,125,161 granted on Nov. 14, 1978 for "Chemical Cutting Apparatus and Method for Use in Wells" (hereafter referred to as the '161 patent). The invention disclosed and claimed herein is directed to an improvement in apparatus subject of the '161 patent, that is, apparatus useful for cutting tubing, pipe and the like in the bore of an oil or gas well.